The long-term goal of this research is to understand the mechanisms involved in speech recognition by the electrically stimulated auditory system, and further, the plasticity of the auditory cortex. The present proposal will address three fundamental questions of speech perception in electric hearing: 1) How are the electrically evoked peripheral neural patterns affected by parametric variations of the speech processor? 2) Ho are the central speech pattern templates reshaped by new peripheral neural patterns? 3) What are the causes of the high variability in speech performance among cochlear implants patients? The hypothesis of this research is that speech recognition in electric hearing is primarily based on a similarity measure between electrically evoked peripheral neural patterns and central speech pattern templates. Based on patients' experience with the implant device, central speech pattern templates can accommodate new peripheral patterns, to some degree. We further hypothesize that a deficit in auditory resolution can remarkably reduce cochlear implant users' capabilities in speech pattern recognition. The significance of this research is not only of theoretical interest in understanding the mechanism involved in speech pattern recognition by electrical stimulation, but also of great clinical importance in designing appropriate speech processors and clinical fitting systems for cochlear implant listeners. It is also possible that principles derived from the present proposals, such as the relation between auditory resolution and speech performance, , are useful to understand the perception problem in hearing-impaired patients.